A preliminary analysis of the temperature-dependent elastic and plastic response of carbon nanotube (CNT) reinforced nanocomposites using an atomistically informed approach is presented. By utilizing molecular dynamics (MD) simulations, the effects of temperature on mechanical properties have been investigated for epoxy-based polymer composites reinforced by randomly dispersed CNTs. A molecular model has been developed for the bulk matrix of the randomly dispersed CNT architecture, and virtual deformation tests have been performed to estimate mechanical properties under a wide range of temperatures. The results indicate that the strength and stiffness of these nanocomposites degrade as the temperature increases and the increase in temperature is linked to an increase in the Poisson’s ratio. This physics-based understanding of the effects of temperature and nanoconfiguration on critical mechanical properties will be valuable for the design optimization of nanocomposites.